Question:
(a) What is meant by a solution ? Give two examples of solutions.
(b)What is a suspension ? Give two examples of suspensions.
(c)
Answer:
(a)A solution is a homogeneous mixture of two (or more substances). A homogeneous mixture means that the mixture is just the same throughout. Some common examples of solutions are : Salt solution, Sugar
(b)A suspension is a heterogeneous mixture in which the small particles of a solid are spread throughout a liquid without dissolving in it. Some common examples of suspensions are : Chalk-water mixture, Muddy water,
(c)A colloid is a kind of solution in which the size of solute particles is intermediate between those in true solutions and those in suspensions.exampl-milk,ink
Is Matter Around Us Pure?
Q 1.
Identify the following as mixture or compound.
(i) blood
(ii) common salt
(iii) sugar
(iv) brass
Q 2.
State the differences between compounds and mixtures.
Q 3.
What is a solution? What are the properties of a solution?
Q 4.
What are the characteristics exhibited by a pure substance?
Q 5.
What are the properties of suspensions?
Q 6.
What are the differences and similarities between concentration and solubility?
Q 7.
What are the reasons for separating the constituents of a mixture?
Q 8.
Name two properties of a substance to check its purity?
Q 9.
What factors affect the solubility of solvent and solute?
Q 10.
What are the physical states of dispersed phase and dispersion medium of a fog?
Q 11.
What are suspensions? Explain with an example.
Q 12.
What is meant by a pure substance?
Q 13.
How crystallization is better than evaporation?
Q 14.
To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293K. Find its concentration at this temperature.
Q 15.
Why air is a mixture not a compound? Give reasons.
Q 16.
What are the advantages of preparing solutions?
Q 17.
Name the elements are in liquid state at room temperature.
Q 19.
Based on the type of solvent, how solutions are classified?
Q 20.
Based on the amount of solute in the given solution, how solutions are classified?
Q 21.
What are the properties of a colloid?
Q 22.
How many elements are there which are in gaseous state at room temperature?
Q 23.
List the points of differences between homogeneous and heterogeneous mixtures.
Q 24.
A good method to separate alum (phitkari) from impure samples is
(a) Filtration
(b) Sedimentaion
(c) Crystallization
(d) Sublimation
Q 25.
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Q 26.
What are the physical states of dispersed phase and dispersion medium of a cloud?
Q 27.
State three reasons why you think air is a mixture and water is a compound.
Q 28.
How will you separate iron pins from sand ?
Q 29.
Name the process you would use to separate a mixture of two miscible liquids (like acetone and water).
Q 30.
Name the technique to separate
(i) butter from curd
(ii) salt from sea-water
(iii) camphor from salt
Q 31.
21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solut water at that temperature.
Q 32.
What is meant by Solubility?
Q 33.
What are the various methods to express concentration of a solution?
Q 34.
What is Chromatography?
Q 35.
Fill in the following blanks with suitable words :
(a) An element is made up of only one kind of...........atoms
(b)Brine is a..........whereas alcohol is a.......
(c) Brass is an alloy which is considered a..........
(d) The three important metalloids are.............and...........
(e) The elements which are sonorous are called...............
Q 36.
Choose one term from the following which includes the other three :
aerosol,
emulsion,
colloid,
sol
Q 37.
What is difference between colloids and suspensions ?
Q 38.
(a) What is a physical change ? Give two examples of physical changes.
(b) What is a chemical change ? Give two examples of chemical changes.
Q 39.
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
Q 40.
Which of the following is a mixture ?Salt, Air, Water, Alum, Sugar
Q 41.
Is air a mixture or a compound ? Give three reasons for your answer.
Q 42.
What are non-aqueous solutions?
Q 43.
Calculate the mass of glucouse and mass of water required to make 200g of 25% solution of glucouse.
Q 44.
Name a metal which is soft and a non-metal which is hard.
Q 45.
Name the process you would use to separate a mixture of water and alcohol.
Q 46.
(a) Name the process by which all the dye can be recovered from black ink.
(b) Name the process by which the various dyes' (coloured materials) present in black ink can be separated.
Q 47.
How would you separate a mixture of sugar and salt ?
Q 48.
What are different categories of pure substance?
Q 49.
Why do fish go in deep waters during day light?
Q 50.
When we open the cap of a cola drink (or any carbonated beverage), why does excess of bubbles come out?
